The field of the present invention relates generally to support mats configured to permit the load of a massive object, such as a vehicle or pedestrian traffic, to move over the surface of permeable turf or graveled areas without significant compaction or other damage to the surface. The present invention relates to such support mats that comprise a plurality of upstanding, open cell members configured for turf to grow through the mat or for gravel to be leveled off to a smooth plane. More particularly, the present invention relates to a system and method for applying markings to such mats, after they have been laid, that will permit vehicles or pedestrians to find their way over the surface to designated parking or movement areas.
As well known to those in the turf and paving industries, there are numerous circumstances when it is necessary or desirable to be able to drive vehicles over turf areas, such as grassy or graveled areas, instead of the typical asphalt, concrete or other solid materials normally used as the load bearing material for roadways or vehicle pathways. Driving vehicles of any substantial weight or at any speeds other than at very low speeds over a turf area can easily result in substantial damage to the turf, particularly if the turf area is wet or configured with turf that is particularly susceptible to damage. Worse yet, vehicles may become bogged down in a saturated surface, requiring extensive damage to the surface in order to extract the vehicle. Despite the potential for damage to the turf, driving vehicles over the turf may occur out of necessity when the turf area is used for temporary or overflow parking, to temporarily connect different parking areas and to permit temporary access across the turf to facilities or for various emergency situations. Allowing vehicles to drive over turf areas is desirable when, often for aesthetic purposes or to avoid interfering with the purpose of the turf area (i.e., golf courses), the owners or operators of the turf areas prefer to not have paths made up of the typical solid roadway materials cutting across the turf area, which would thereby divide the turf area into disconnected segments. Examples of turf areas where the use of standard roadway materials are often not desired include golf cart paths, service roads through or overflow parking areas in parks and other park-like areas, residential driveways, emergency vehicle access lanes, grass air strips and the like. As well known, movement of vehicles across the turf can result in ruts in the turf, tearing of the turf and undesirable compaction of the turf and/or soil underneath that can inhibit or prevent normal turf growth.
To prevent damage to the turf from the movement of vehicles, such as cars, trucks, golf carts, emergency vehicles and other such vehicles, across or through the turf area it is common to utilize load bearing mats embedded or otherwise placed in or on the turf. Commonly, these load bearing mats are made up of a plurality of individual mat units and generally configured with a plurality of connected cell or cell-like members that are of sufficient strength and surface area to support the weight of the vehicle or other load bearing traffic as it moves over the turf. Many of the load bearing mats have cell members that are configured, at least to a certain extent, to allow the turf to grow through the load bearing mat and to allow water and other nutrients to reach the roots of the turf. The load bearing mats are typically placed in the turf or soil base just below the grade level of the turf so that conventional turf equipment, including lawnmowers and the like, can move over the turf and cut or treat the turf. To allow for different sizes of areas where load bearing mats are utilized, the typical load bearing mat is provided in modular mat units that can be selectively connected together to provide the desired amount of load bearing surface (i.e., parking lot sized area). The area enclosed by the cell members are filled with soil or other materials. In turf areas, the fill material preferably comprises that which facilitates the growth of turf through the load bearing mat. To facilitate gripping of the subsurface by the load bearing mat, drainage through the turf and oxygen transfer by the turf, it is generally desirable that the base of the individual cell members have as much opening as possible.
The use of load bearing mats to provide support in turf areas is not limited to use with areas where vehicles may move across or through the turf area. In addition, load bearing mats are also utilized in areas subject to heavy pedestrian or other non-vehicle load bearing traffic, such as for walking and/or bicycle paths through a park or park-like settings. Use of load bearing mats are also beneficially utilized on campus open areas where students are likely to cut across the turf and in areas around nursing homes or hospitals where persons may want to push another person in a wheelchair or use other equipment. Use of load bearing mats to prevent damage to turf is known to be particularly advantageous in areas where water or other fluids may commonly collect after watering or rain.
Examples of load bearing mats for use in turf areas can be found in numerous prior art patents. For instance, U.S. Pat. No. 4,621,942 to Hill describes a grass paving structure having a plurality of honeycombed, hexagon-shaped cells with upstanding sidewalls and a plurality of openings in the underlying base surface. In one configuration, as sold by National Diversified Sales, Inc. (the assignee of the present invention) under the name Tufftrack® Grassroad Pavers, the load bearing members are sold in two foot by two foot interlocking sections that can be connected together to cover any size of area.
Another example is U.S. Pat. No. 7,210,876 to Moralez, which also describes a grass paving structure having a plurality of honeycombed, hexagon-shaped cells with upstanding sidewalls and a plurality of openings in the underlying base surface. In this configuration, as sold by National Diversified Sales, Inc. under the name EZ Roll® Grass Pavers, the load bearing members are sold in interlocking sections that can be connected together to cover any size of area. However, in this configuration, the sections can be rolled into a large cylindrical roll which makes transportation and placement much easier.
In the described context of such reinforced paving structures for turf areas, a further problem has become apparent. Such paving structures have proven to be so successful in their general purpose that it is now common to see traffic directed onto reinforced turf areas in volumes high enough to give rise to traffic congestion and related problems. For example, a large open field may have its surface reinforced to provide general access to scores, or perhaps even hundreds, of vehicles at a sporting event. In order to control the efficient parking of these vehicles, organizers may typically place cones on, or insert flags into, the turf surface to direct traffic. Alternatively, the turf surface may be painted or marked with lime powder according to known methods. However, these are temporary measures, because any imposed structures must be subsequently removed, and paint or lime will wash away within a short period of time. Thus, there is a constant need to install and remove, and generally manage the markers on such a reinforced surface from time to time when the surface is used for traffic. This may become a labor intensive activity with attendant problems.
Thus there is a need in the art for a more permanent system and method of marking reinforced paving structures for use by traffic. The present invention addresses these and other needs.